n = int(input())
p = n // 15
ans_1 = p * 16
q = n % 15
if q >= 12:
    ans_2 = 12
elif q >= 10:
    ans_2 = 10
elif q == 9:
    ans_2 = 8
elif q >= 6:
    ans_2 = 6
elif q == 5:
    ans_2 = 4
elif q >= 3:
    ans_2 = 2
else:
    ans_2 = 0

print(ans_1 + ans_2)